A wide variety of products today are produced from fiberglass mats. For example, many modern roofing materials are made from fiberglass mat. This includes both the roll material which are used in place of the asphalt-impregnated felt materials employed in the plys of flat roofs, as well as in the smaller shingles often found on residential roofs.
In the past, fiberglass mats which could be converted into these roofing materials were normally produced in a dry process. They comprised a combination of chopped glass fibers in a cured binder material which, preferably, was water resistant. In such dry processes, the chopped fibers were usually distributed over a formation surface by some available means, such as air pressure which would blow the fibers around until they landed on the surface. Unfortunately, it has been found that the fibers do not distribute properly in these dry processes, leaving portions of the resultant product dangerously weak. More importantly, mats formed in this manner have little or no ability to resist tearing when a force in any direction is applied to the mat.
In order to overcome these difficulties, it has been proposed at various times to install continuous slivers or strands of fiberglass in the mats prior to application of the binder. Such a process has been shown, for example, in U.S. Pat. No. 2,731,066 to Hogendobler, et al.
Unfortunately, the mats produced by such processes have been deficient due to inherent mechanical weaknesses. For example, there still exists a distribution problem with respect to the chopped glass fibers. Further, since such processes do not try to locate the continuous strands on a single cross-sectional plane, such mats still have insufficient tear strength. The indiscriminate vertical dispersion of the strands within the mats decrease their mechanical strength and often results in the final product separating into longitudinal strips or laminae.
Further, it has been found that the dry process for production of fiberglass matting is much too slow to meet the production requirements generated by the need for roofing materials in construction and repair, as well as by other products utilizing such mats.
Recently, a wet process for producing fiberglass matting has been developed in some foreign countries. This process is superior to the dry process in that the rate of production is much greater and the chopped glass fibers are relatively uniformly distributed throughout the mass. However, such processes have not been able to employ the reinforcing strands discussed previously with respect to the dry process as shown in the Hogendobler, et al. patent.
Consequently, while such wet process matting can be produced at a more rapid pace with a more uniform distribution of the glass fibers, it has been unable to resist tearing when a force is applied to the matting in almost any direction. This is not totally unsatisfactory in the foreign countries concerned, since construction there is accomplished at a much more leisurely pace and the material can be more carefully handled. In the United States, on the other hand, such materials have failed to withstand the rough handling generated by the speed with which such products must be handled and applied in construction.
Consequently, a very pressing need for a uniform, high-production speed, relatively strong fiberglass matting has developed and that need has, heretofore, not been satisfied by the industry.